<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #div1{
            width: 100px;
            height: 100px;
            background-color: pink;
            /*隐藏div1*/
            /*visibility: hidden;*/
            display: block;
        }
        #div1:hover{
            display: none;
        }
    </style>
</head>
<body>
<!--元素的隐藏方式
visibility：hidden
display：none
-->
<div>
    <div id="div1">div1</div>
    <div id="div2">div2</div>
    <div id="div3">div3</div>
</div>
</body>
</html>